<template>
  <div class="drag" ref="dragDiv">
    <div class="drag_bg"></div>
    <div class="drag_text">{{confirmWords}}</div>
    <div ref="moveDiv"
         @touchmove.stop="touchMoveFn($event)"
         @touchstart.stop="touchStartFn($event)"
         @touchend.stop="touchEndFn($event)"
         @mousedown="mousedownFn($event)" :class="{'handler_ok_bg':confirmSuccess}" class="handler handler_bg" style="border: 0.5px solid #e6e6e6;height: 40px;position: absolute;top: 0px;left: 0px;"></div>
  </div>

</template>

<script>
  export default {
    name:"JSlider",
    data(){
      return {
        beginClientX:0,           /*距离屏幕左端距离*/
        mouseMoveStata:false,     /*触发拖动状态  判断*/
        maxwidth:'',               /*拖动最大宽度，依据滑块宽度算出来的*/
        confirmWords:'拖动滑块验证',   /*滑块文字*/
        confirmSuccess:false           /*验证成功判断*/
      }
    },
    methods: {
      isSuccess(){
        return this.confirmSuccess
      },
      touchEndFn(e) {
        this.mouseMoveStata = false
        let element = e.changedTouches[0]
        let width = element.clientX - this.beginClientX

        if(width<this.maxwidth&&this.confirmSuccess != true) {
          document.getElementsByClassName('handler')[0].style.left = '0px'
          document.getElementsByClassName('drag_bg')[0].style.width = '0px'
        }
      },
      touchMoveFn(e) {
        if(this.mouseMoveStata) {
          let element = e.targetTouches[0]
          let width = element.clientX - this.beginClientX
          if(width>0 && width<=this.maxwidth){
            document.getElementsByClassName('handler')[0].style.left = width + 'px'
            document.getElementsByClassName('drag_bg')[0].style.width = width + 'px'
          }else if(width>this.maxwidth){
            this.successFunction();
          }
        }
      },
      touchStartFn: function(e) {
        if(!this.confirmSuccess) {
          e.preventDefault && e.preventDefault();
          let element = e.targetTouches[0]
          this.mouseMoveStata = true
          this.beginClientX = element.clientX
        }
      },
      mousedownFn:function (e) {
        if(!this.confirmSuccess){
          e.preventDefault && e.preventDefault();   //阻止文字选中等 浏览器默认事件
          this.mouseMoveStata = true;
          this.beginClientX = e.clientX;
        }
      },        //mousedoen 事件
      successFunction(){
        this.confirmSuccess = true
        this.confirmWords = '验证通过';
        if(window.addEventListener){
          document.getElementsByTagName('html')[0].removeEventListener('mousemove',this.mouseMoveFn);
          document.getElementsByTagName('html')[0].removeEventListener('mouseup',this.moseUpFn);
        }else {
          document.getElementsByTagName('html')[0].removeEventListener('mouseup',()=>{});
        }
        document.getElementsByClassName('drag_text')[0].style.color = '#fff'
        document.getElementsByClassName('handler')[0].style.left = this.maxwidth + 'px';
        document.getElementsByClassName('drag_bg')[0].style.width = this.maxwidth + 'px';

        this.$emit("onSuccess",true)
      },                //验证成功函数
      mouseMoveFn(e){
        if(this.mouseMoveStata){
          let width = e.clientX - this.beginClientX;
          if(width>0 && width<=this.maxwidth){
            document.getElementsByClassName('handler')[0].style.left = width + 'px';
            document.getElementsByClassName('drag_bg')[0].style.width = width + 'px';
          }else if(width>this.maxwidth){
            this.successFunction();
          }
        }
      },                   //mousemove事件
      moseUpFn(e){
        this.mouseMoveStata = false;
        var width = e.clientX - this.beginClientX;
        if(width<this.maxwidth){
          // ---- update-begin- author:sunjianlei --- date:20191009 --- for: 修复获取不到 handler 的时候报错 ----
          let handler = document.getElementsByClassName('handler')[0]
          if (handler) {
            handler.style.left = 0 + 'px'
            document.getElementsByClassName('drag_bg')[0].style.width = 0 + 'px'
          }
          // ---- update-end- author:sunjianlei --- date:20191009 --- for: 修复获取不到 handler 的时候报错 ----
        }
      }                       //mouseup事件
    },
    mounted(){
      this.maxwidth = this.$refs.dragDiv.clientWidth - this.$refs.moveDiv.clientWidth;
      document.getElementsByTagName('html')[0].addEventListener('mousemove',this.mouseMoveFn);
      document.getElementsByTagName('html')[0].addEventListener('mouseup',this.moseUpFn)
    }
  }
</script>

<style scoped>
  .drag{
    position: relative;
    background-color: #e8e8e8;
    width: 100%;
    height: 40px;
    line-height: 40px;
    text-align: center;
  }
  .handler{
    width: 40px;
    height: 32px;
    border: 1px solid #bfbfbf;
    cursor: move;
    box-shadow: 0 0 1px #bfbfbf;
  }
  .handler_bg{
    background: #fff url("") no-repeat center;
  }
  .handler_ok_bg{
    background: #fff url("") no-repeat center;
  }
  .drag_bg{
    background-image: linear-gradient(to right,#32be8f,#38d39f,#32be8f);
    height: 40px;
    width: 0px;
  }
  .drag_text{
    position: absolute;
    top: 0px;
    width: 100%;text-align: center;
    -moz-user-select: none;
    -webkit-user-select: none;
    user-select: none;
    -o-user-select:none;
    -ms-user-select:none;
  }
</style>
